Manufacturing method of semiconductor device

摘要

A semiconductor device using an oxide semiconductor is provided with stable electric characteristics to improve the reliability. In a manufacturing process of a transistor including an oxide semiconductor film, an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a first crystalline oxide semiconductor film) is formed; oxygen is added to the oxide semiconductor film to amorphize at least part of the oxide semiconductor film, so that an amorphous oxide semiconductor film containing an excess of oxygen is formed; an aluminum oxide film is formed over the amorphous oxide semiconductor film; and heat treatment is performed thereon to crystallize at least part of the amorphous oxide semiconductor film, so that an oxide semiconductor film containing a crystal having a c-axis which is substantially perpendicular to a top surface thereof (also called a second crystalline oxide semiconductor film) is formed.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming an oxide semiconductor film over an insulating film; forming a gate insulating film over the oxide semiconductor film; forming a gate electrode layer over the gate insulating film; adding oxygen to the oxide semiconductor film after forming the gate electrode layer.